Vol. 12, Issue 12 (2023)

Author(s):
Prakash, Anand Naik, Siddaram, Ravi MV and Bellakki MA

Abstract:
The application of fertilizers in the right quantity and balanced manner at the right time is an important factor in enhancing the productivity of crops. Among different major nutrients, nitrogen and phosphorus are applied in high dose and the nutrient use efficiency of nitrogen is only 30 to 50 per cent. The remaining 50 to 70 per cent is lost due to volatilization, deep percolation and weed clearance. In case of phosphorus usage efficiency is just 15 to 20 per cent and remaining is lost due to soil fixation. Hence, nanotechnology assumes a greater role in reaching this task. Along with advancements in science, nano fertilizers or nano encapsulated nutrients are shown to have properties that are effective to crop. The nutrients on demand, controlled release of chemical fertilizers that regulate the plant growth and enhance yield. These fertilizers are appropriate alternatives to conventional fertilizers for a gradual and controlled supply of nutrients in the crops. The experiment was laid out in Randomized Complete Block Design with three replications. A field experiment was carried out in medium black soil at ICAR-KVK, Kalaburagi, during Kharif 2022 for one year. There were nine treatment combinations, consisting of different doses of RDF i.e., 50%, 75%, 100% RDF and absolute control along with different doses of nano DAP foliar spray @ 2 and 4 ml L^-1. Application of 100% RDF as basal and nano DAP foliar spray @ 4 ml L^-1 at 30 and 45 DAS recorded significantly higher plant height at harvest (37.4 cm), total dry matter production at harvest (37.20 g plant^-1), higher seed yield (2095 kg ha^-1) and stover yield (3735 kg ha^-1). It also produced higher net returns (61,305 Rs. ha^-1) and BC ratio (2.86). However, lower growth, yield and economics was noticed in absolute control. Combined application of RDF @ 100% and two foliar sprays of nano DAP @ 2 ml L^-1 at 30 and 45 DAS increased the growth, yield and economics of soybean.